The present technology relates to a power supply switching circuit, an electronic device, and a control method of the power supply switching circuit. In particular, the present technology relates to a power supply switching circuit that switches between a main power supply and a power supply from a battery, an electronic device, and a control method of the power supply switching circuit.
A battery backup system has been used in electronic devices such as computers so that data is not lost even if the supply from the main power supply is stopped. In the battery backup system, a standby power supply from a battery is supplied to a storage apparatus when the supply from the main power supply is stopped so that necessary data is stored in the storage apparatus.
To realize the battery backup system, a power supply switching circuit including a comparator, an inverter, and two transistors is proposed (see, for example, JP 2006-254672A). In the power supply switching circuit, the comparator compares the voltage of the main power supply and the voltage of a battery and the inverter inverts the comparison result. Then, one of the two transistors outputs or shuts off the main power supply based on the comparison result and the other transistor outputs or shuts off the standby power supply based on the inverted comparison result. Accordingly, power of one of the AC power supply and the battery having a higher voltage is supplied to a load.